Vehicle seatbelt assembly

ABSTRACT

A vehicle seatbelt assembly includes a load limiter having a seatbelt attachment portion and a seatbelt tension control mechanism that is configured to increase the length of a shoulder portion of a seatbelt in response to rapid or sudden deceleration of a vehicle, thereby reducing a level of tension experience by a seatbelt.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/621,834 filed on Jun. 13, 2017. The entiredisclosure of U.S. patent application Ser. No. 15/621,834 is herebyincorporated herein by reference in its entirety.

BACKGROUND Field of the Invention

The present invention generally relates to a seatbelt assembly having aload limiter. More specifically, the present invention relates to aseatbelt assembly with a load limiter that allows a shoulder portion ofa seatbelt to increase in length by a predetermined distance therebyreducing tension on the shoulder portion of the seatbelt in response torapid or sudden deceleration of a vehicle.

Background Information

When a vehicle in motion undergoes rapid and/or sudden deceleration, apassenger within the vehicle responds in accordance with Newton's lawsof motion such that momentum of the passenger imparts forces to aseatbelt restraining the passenger thereby transferring force to theseatbelt. The transferred force puts the seatbelt under tension.

SUMMARY

One object of the present disclosure is to provide a seatbelt assemblywith a load limiter that selectively allows an increase in length of ashoulder portion of a seatbelt in response to rapid or suddendeceleration of a vehicle, thereby reducing a level of tensionexperience by the seatbelt.

In view of the state of the known technology, one aspect of the presentdisclosure is to provide a vehicle with a seatbelt assembly load limiterhaving a seatbelt attachment portion and a seatbelt tension controlmechanism that is configured to increase the length of a shoulderportion of a seatbelt in response to rapid or sudden deceleration of avehicle, thereby reducing a level of tension experience by a seatbelt.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a side view of a vehicle with a passenger compartment havingseatbelt assemblies in accordance with a first embodiment;

FIG. 2 is a perspective view of the passenger compartment of the vehicledepicted in FIG. 1, showing seats and seatbelt assemblies in accordancewith the first embodiment;

FIG. 3 is a front view of one of the seats of the vehicle depicted inFIGS. 1 and 2, showing a load limiter of the seatbelt assembly inaccordance with the first embodiment;

FIG. 4 is a side view of a portion of the seat depicted in FIG. 3,showing schematic details of the load limiter of the seatbelt assemblyin accordance with the first embodiment;

FIG. 5 is a schematic exploded perspective view of the load limitershowing details a first member, a second member, a buckle mechanism, anda clutch mechanism of the load limiter in accordance with the firstembodiment;

FIG. 6 is a partial exploded perspective view of the load limiter of theseatbelt assembly shown partially assembled in accordance with the firstembodiment;

FIG. 7 is a cross-sectional view of the load limiter taken along theline 7-7 in FIG. 4 in accordance with the first embodiment;

FIG. 8 is a cross-sectional view of a portion of the load limitershowing the clutch mechanism, the clutch mechanism includes amagnetorheological material in a dis-engaged state in accordance withthe first embodiment;

FIG. 9 is a cross-sectional view of a portion of the load limitershowing the clutch mechanism in an engaged state in accordance with thefirst embodiment;

FIG. 10 is a schematic view of the seatbelt assembly showing the secondmember, the buckle mechanism, the buckle mechanism and the clutchmechanism in an at rest position relative to the first member inaccordance with the first embodiment;

FIG. 11 is another schematic view of the portion of the seatbeltassembly showing the second member, the buckle mechanism, and the clutchmechanism of the load limiter in one of a plurality of releasedpositions relative to the first member in accordance with the firstembodiment;

FIG. 12 is still another schematic view of the portion of the seatbeltassembly showing the second member, the buckle mechanism, and the clutchmechanism in another of the plurality of released positions of the loadlimiter relative to the first member in accordance with the firstembodiment;

FIG. 13 is a block diagram showing a controller and sensor connected tothe load limiter, the controller being configured to operate the clutchmechanism of the load limiter in accordance with the first embodiment;

FIG. 14 is a cross-sectional view similar to FIG. 7 showing a loadlimiter with a clutch mechanism that extends around the pivot pin withthe load limiter in an at rest state in accordance with a secondembodiment;

FIG. 15 is another cross-sectional view similar to FIG. 14 showing theload limiter in one of the released positions in accordance with thesecond embodiment;

FIG. 16 is a schematic exploded perspective view of a load limitershowing details the first member, the second member, the bucklemechanism, the clutch mechanism and a position adjusting mechanism ofthe load limiter in accordance with a third embodiment;

FIG. 17 is a partial exploded perspective view of the load limiterdepicted in FIG. 16 shown partially assembled in accordance with thethird embodiment;

FIG. 18 is a schematic exploded perspective view of a load limitershowing details the first member, the second member, the bucklemechanism, the clutch mechanism and a position adjusting mechanism ofthe load limiter in accordance with a fourth embodiment; and

FIG. 19 is a partial exploded perspective view of the load limiterdepicted in FIG. 18 shown partially assembled in accordance with thefourth embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Selected embodiments will now be explained with reference to thedrawings. It will be apparent to those skilled in the art from thisdisclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

Referring initially to FIGS. 1 and 2, a vehicle 10 with a passengercompartment 12 having a plurality of seatbelt assemblies 14 isillustrated in accordance with a first embodiment.

The vehicle 10 includes a vehicle body structure 16 that defines thepassenger compartment 12. The vehicle body structure 16 includes, amongother features, a floor 20, pillar structures 22 and a roof structure 24that at least partially surround the passenger compartment 12.

A plurality of seat structures 26 are installed within the passengercompartment 12 of the vehicle 10. Each of the seat structures 26includes at least one of the plurality of seatbelt assemblies 14.

Since each of the seatbelt assemblies 14 is basically identical, havingbasically the same features and structures associated therewith, onlyone seatbelt assembly 14 is described herein below for the sake ofbrevity.

As shown in FIG. 3, the seatbelt assembly 14 includes a seatbelt 30, aseatbelt latch tongue member 32 and a load limiter 34.

As shown in FIG. 3, the seatbelt 30 has a first end 30 a non-movablyfixed relative to a portion of the seat structure 26 or the floor 20,and a second end 30 b retractably retained within the passengercompartment 12. For example, the second end 30 b can retract into aretraction device 30 c that is fixed to an adjacent one of the pillarstructure 22 in a conventional manner. The seatbelt latch tongue member32 is installed to the seatbelt 30 for sliding movement along theseatbelt 30. The seatbelt latch tongue member 32 further divides theseatbelt 30 into a shoulder portion 30 d and a lap portion 30 e. Asshown in FIG. 3, the shoulder portion 30 d extends from the seatbeltlatch tongue member 32 across the torso and shoulder of a passengerseated in the seat structure 26. The lap portion 30 e extends from theseatbelt latch tongue member 32 across the hip and upper thigh area ofthe passenger.

The load limiter 34 includes a first member 36, a second member 38, abuckle mechanism 40, a clutch mechanism 42 and an electronic controller44 (FIG. 11), and is described in greater detail below with respect toFIGS. 5-10. As shown in FIGS. 3 and 4, the first member 36 of the loadlimiter 34 is attached to the seat structure 26. However, the firstmember 36 can alternatively be attached to the floor 20 of the passengercompartment 12.

The seatbelt latch tongue member 32 is configured to releasably attachto the latch device of the buckle mechanism 40 in a conventional manner.The buckle mechanism 40 therefore defines a seatbelt attachment portionof the load limiter 34. Since seatbelts, seatbelt latch tongue membersand retraction devices 30 c are conventional features, furtherdescription is omitted for the sake of brevity.

A description of the load limiter 34 is now provided with specificreference to FIGS. 5-13. As mentioned above, in the first embodiment,the first member 36 is fixedly attached to the seat structure 26 in aconventional manner. The first member 36 can be non-movably fixed to theseat structure 26, or, alternatively the first member 36 can beconfigured to pivot relative to the seat structure 26. In the firstembodiment, the first member 36 is non-movably fixed to the seatstructure 26. The attachment between the seat structure 26 and the firstmember 36 is of sufficient strength and design to withstand forcesreceived from the seatbelt assembly 14. For example, a bolt or pivot pin(not shown) can be installed through an aperture (not shown) in thefirst member 36, and extend into a metallic frame (not shown) of theseat assembly 14, where the bolt serves as a pivot axis. Since pivotattachments and metallic frames of seat assemblies are conventionalstructures, further description is omitted for the sake of brevity.

As shown in FIGS. 5 and 6, the first member 36 includes a housing 50, acover 52 and biasing members 54. The housing 50 and the cover 52 areprovided with an elongated slots 50 a and 52 a that align with oneanother when the cover 52 is fixedly attached to the housing 50. Thecover 52 can be fixed to the housing 50 via fasteners F₁. The housing 50defines a recessed portion 50 b that is dimensioned to receive thesecond member 38 and the biasing members 54. As shown in FIGS. 6 and 7,the biasing members 54 are positioned within the recessed portion 50 bsuch that the biasing members 54 urge the second member 38 into an atrest position that is described further below.

The biasing members 54 can be metallic coil springs, pneumatic pistons,or any of a variety of conventional devices that can be used to apply abiasing force in a manner that biases the second member 54 as describedherein. The first member 36, the second member 38 and the clutchmechanism 42 define a seatbelt tension control mechanism.

The second member 38 is installed within the recessed portion 50 b ofthe housing 50 and therefore is supported on the first member 36 suchthat the second member 38 is configured for limited sliding movementrelative to the first member 36 within the recessed portion 50 b of thehousing 50 of the first member 36. Consequently, the second member 38 isdimensioned such that the second member 38 is slidable within therecessed portion 50 b of the housing 50 of the first member 36.

The buckle mechanism 40 is attached to the second member 38 for movementtherewith via a pivot pin 58, as shown in FIGS. 5 and 6. The pivot pin58 is dimensioned to extend through an opening in the buckle mechanism40, through an opening in the clutch mechanism 42, through the slot 52 bof the cover 52, through an opening in the second member 38 and throughthe slot 50 a of the housing 50 of the first member 36. The pivot pin 58can include a threaded portion that is threadedly engages the secondmember 38, or and be fixed in place by a threaded nut (FIG. 7) on a backside of the first member 36. Regardless of its attachments, the pivotpin 58 is configured to allow the second member 38, the buckle mechanism40 and the clutch mechanism 42 to slide as a single unit relative to thefirst member 36 and allow the buckle mechanism 40 to pivot relative tothe second member 38 and the clutch mechanism 42. The pivot pin 58further defines a coupling member that connects the buckle mechanism 40to the second member 38.

The buckle mechanism 40 also includes a conventional latch device forconnection to the seatbelt latch tongue member 32. Since latch devicesin buckle mechanisms are conventional structures and mechanisms, furtherdescription is omitted for the sake of brevity.

The clutch mechanism 40 is operably disposed between the first member 36(outside the housing 50) and the second member 38. Since the bucklemechanism 40 and the clutch mechanism 42 are attached to the secondmember 38 via the pivot pin 58, the buckle mechanism 40 and the clutchmechanism 42 are structurally part of the second member 38 and movetherewith relative to the first member 36.

The clutch mechanism 40 is operable to switch between a dis-engagedstate allowing movement of the second member 38 relative to the firstmember 36 and an engaged state preventing movement of the second member38 relative to the first member 36. The clutch mechanism 42 can be anyof a variety of structures and mechanisms that expand (engagedstate—FIG. 9) and contract (dis-engaged state—FIG. 8) between the headof the pivot pin 58 and the housing 50. More specifically, when theclutch mechanism 42 is in an expanded state (the engaged state), theclutch mechanism 42 clamps itself between the head of the pivot pin 58and the adjacent surfaces of the housing 50, thereby preventing movementof the clutch mechanism 42, the buckle mechanism 40 and the secondmember 38 relative to the housing 50 of the first member 36.

In the depicted embodiments as shown in FIGS. 8 and 9, the clutchmechanism 42 includes an outer housing 42 a that defines sealed chamberfilled with magnetorheological liquid 42 b. A first electrode 42 c islocated at one side of the sealed chamber and a second electrode 42 d islocated at an opposite side of the sealed chamber of the housing 42 a.The clutch mechanism 42 is activated via application of an electriccurrent across the first electrode 42 c and the second electrode 42 d.Specifically, the clutch mechanism 42 is electronically activated whenthe electric current is provided to flow from the first electrode 42 cto the second electrode 42 d. Thereafter, the clutch mechanism 42 is inthe engaged state with particles in the magnetorheological liquidbecoming linearly aligned causing the housing 42 a to expand indirections parallel to the pivot pin 58, as shown in FIG. 9. In theabsence of an electric current to the clutch mechanism 42, the clutchmechanism 42 contracts to the dis-engaged state with themagnetorheological liquid moving to more random orientations (a lack oflinear alignment) that takes up less volume, as shown in FIG. 8. Sincethe response of magnetorheological liquid to electrical current is aconventional technology, further description is omitted for the sake ofbrevity.

In the first embodiment, the housing 42 a can be made of any of avariety of materials that allow limited movement in response to changesin the alignment of the magnetorheological liquid disposed therein. Forexample, the housing 42 a can be made of a plastic or polymer material,or can be made of a thin flexible metallic material or alloy.

As shown in FIG. 10, the second member 38 (not visible in FIG. 10), thebuckle mechanism 40 and the clutch mechanism 42 are in an at restposition (a first orientation) with the second member 38 being biased bythe biasing members 54 to a lower end of the recessed portion 50 b ofthe housing 50 of the first member 36. As shown in FIG. 11, in responseto a first level of tension being applied to the shoulder portion 30 dof the seatbelt 30, the force of the biasing members 54 is partiallyovercome, allowing the second member 38 (not visible in FIG. 11), thebuckle mechanism 40 and the clutch mechanism 42 to move to one of aplurality of released positions, with the clutch mechanism 42 beingdis-engaged. As shown in FIG. 12, in response to a second level oftension greater than the first level of tension being applied to theshoulder portion 30 d of the seatbelt 30, the force of the biasingmembers 54 is further overcome, allowing the second member 38 (notvisible in FIG. 12), the buckle mechanism 40 and the clutch mechanism 42to move to another of the plurality of released positions, with theclutch mechanism 42 being dis-engaged.

As is explained in greater detail below, the operation of the clutchmechanism 42 to the engaged state is usually implement with the secondmember 38, the buckle mechanism 40 and the clutch mechanism 42 in the atrest position shown in FIG. 10. At this time, the buckle mechanism 40 isa first distance (a predetermined distance) away from the first member36 with the clutch mechanism 42 in the engaged state. In response to thecontroller 44 operating the clutch mechanism 42 to change from theengaged state to the dis-engaged state, movement of the second member38, the buckle mechanism 40 and the clutch mechanism 42 relative to thefirst member 36 in response to tension on the shoulder portion 30 d ofthe seatbelt 30 changes the location of the buckle mechanism 40 suchthat the buckle mechanism 40 is a second distance away from the firstmember 36, the second distance being greater than a first distance, asshown in FIGS. 11 and 12.

A description of the controller 44 and its operation is now providedwith specific reference to FIG. 13. The controller 44 is connected tothe clutch mechanism 42 (and all other clutch mechanisms of otherseatbelt assemblies), to airbags 1-N, an impact sensor 46 (or impactsensors) and a motion detector or accelerometer sensor 48. Thecontroller 44 is configured to operate the clutch mechanism 42 to changefrom dis-engaged state to the engaged state upon initial detection of atensioning event, and after a predetermined period of time, for exampleanywhere from 100 ms to 1 second, the controller 44 operates the clutchmechanism 42 to change from the engaged state to the dis-engaged state.

Tensioning events can be any one of the following: a rapid decelerationof the vehicle body structure 16, a hard-braking event or an impactevent. A rapid deceleration of the vehicle body structure 16 can occurwhen the vehicle engages deep water (greater than two or three inches ofwater). A hard-braking event occurs when a vehicle operator applies ahard braking force to the brake pedal (not shown) of the vehicle 10 fora prolonged period of time (more that 1-2 seconds). An impact event isan event where the vehicle 10 impact another vehicle, or a fixedbarrier. The various tensioning events cause the vehicle 10 to rapidlydecrease speed (velocity) thereby causing a rapid deceleration detectedby the motion detector or accelerometer sensor 48, or during an impactevent, signals from the impact sensor or sensors 46. The rapiddeceleration can last for several seconds, or only an instant.Regardless, the controller 44 can be configured to engage the clutchmechanism 42 briefly and then release the clutch mechanism 42 so thatthe buckle mechanism 42 can move against the force of the biasingmembers 54 thereby allowing the shoulder portion 30 d of the seatbelt 30to increase slightly in length. The change in length of the shoulderportion 30 d of the seatbelt 30 allows the torso and shoulder areas of apassenger to move forward slightly, reducing the force felt by thepassenger by the seatbelt 30. The initial engagement of the clutchmechanism 42 restricts initial movement of the passenger absorbingenergy associated with forward momentum, and thereafter thedis-engagement of the clutch mechanism 42 relieves some the forcesacting between the seatbelt 30 on the torso and shoulder areas of thepassenger during rapid deceleration of the vehicle 10.

When the clutch mechanism 42 is initially engaged by the controller 44as shown in FIG. 10, the clutch mechanism 42 retains the second member38 in the at rest position (also referred to as the first orientation)relative to the first member 36. Thereafter, when the controller 44dis-engages the clutch mechanism 42 as shown in FIGS. 11 and 12, thesecond member 38 can move to any one of the plurality of releasedpositions, cushioned by the force of the biasing members 54.

It should be understood from the drawings and the description hereinthat the controller 44 can deploy the airbags depicted in FIG. 13,depending upon the circumstances detected during the tensioning event.For example, if the tensioning event is an impact event, activated onesof the airbags can be deployed. However, if the tensioning event is ahard-braking event or a rapid deceleration event in the absence of animpact event, the controller 44 can only operate the clutch mechanism42, as described above.

Second Embodiment

Referring now to FIGS. 14 and 15, a seatbelt assembly 114 that includesa load limiter 134 in accordance with a second embodiment will now beexplained. In view of the similarity between the first and secondembodiments, the parts of the second embodiment that are identical tothe parts of the first embodiment will be given the same referencenumerals as the parts of the first embodiment. Moreover, thedescriptions of the parts of the second embodiment that are identical tothe parts of the first embodiment may be omitted for the sake ofbrevity.

The load limiter 134 of the second embodiment includes many of thefeatures of the load limiter 34 of the first embodiment, including, thefirst member 36 with its housing 50, the cover 52, the biasing members54, the second member 38, the buckle mechanism 40 and the pivot pin 58.However, in the second embodiment, a clutch mechanism 142 replaces theclutch mechanism 42. In the second embodiment, the clutch mechanism 142includes a main portion 142 a, a cylindrical portion 142 b and asecondary portion 142 c. The main portion 142 a, the cylindrical portion142 b and the secondary portion 142 c are formed as a single element orassembly and are filled with the magnetorheological fluid, as with thefirst embodiment. The main portion 142 a is disposed between the bucklemechanism 40 and the housing 50 of the first member 36. The cylindricalportion 142 b surrounds the pivot pin 58 and includes an opening thatthe pivot pin 58 extends through. The secondary portion 142 c is locatedbetween the housing 50 and a nut that secures the pivot pin 58 in place.When the clutch mechanism 142 is in an engaged state, all portions ofthe clutch mechanism 142 increase in size, clamping the pivot pin 58 inplace relative to the housing 50. When the clutch mechanism 142 is in adis-engaged state, the buckle mechanism, the second member 38 and thepivot pin 58 can slide relative to the first member 36 against thebiasing force of the biasing members 54.

Third Embodiment

Referring now to FIGS. 16 and 17, a seatbelt assembly 214 that includesa load limiter 234 in accordance with a third embodiment will now beexplained. In view of the similarity between the first and thirdembodiments, the parts of the third embodiment that are identical to theparts of the first embodiment will be given the same reference numeralsas the parts of the first embodiment. Moreover, the descriptions of theparts of the third embodiment that are identical to the parts of thefirst embodiment may be omitted for the sake of brevity.

The load limiter 234 of the third embodiment includes many of thefeatures of the load limiter 34 of the first embodiment, including, thecover 52, the second member 38, the buckle mechanism 40, the clutchmechanism 42 and the pivot pin 58. However, in the third embodiment, thefirst member 36 and housing 50 have been replaced with a first member236 and housing 250. Further, the two biasing members 54 have beenreplaced with four biasing members 254. Two of the biasing members 254are installed within the housing 250 at a first side of the secondmember 38, and two of the biasing members 254 are installed at a secondside of the second member 38. Further, a position adjusting mechanismhaving a motor 260 and a connecting cable 262 is connected to the motor260 and the second member 38.

In the third embodiment, the second member 38 is biased by the fourbiasing members 254 to an at rest position that is centrally locatedwithin the recessed portion 50 b of the housing 250, as shown in bothFIGS. 16 and 17. The motor 260 of the position adjusting mechanism isoperated to adjust the at rest position of the second member 38 and thebuckle mechanism 40 for the comfort of the passenger. Specifically, themotor 260 applies force to the connecting cable 262 pulling on it tochange the at rest position of the second member 38 relative to thehousing 50. When the controller 44 is provided with signals from one orboth of the sensors 46 and 48 indicating a tensioning event, the motor260 releases any tension applied to the cable 262 allowing the clutchmechanism 42 to be operated in the manner described above with respectto the first embodiment.

Fourth Embodiment

Referring now to FIGS. 18 and 19, a seatbelt assembly 314 that includesa load limiter 334 in accordance with a fourth embodiment will now beexplained. In view of the similarity between the first and fourthembodiments, the parts of the fourth embodiment that are identical tothe parts of the first embodiment will be given the same referencenumerals as the parts of the first embodiment. Moreover, thedescriptions of the parts of the fourth embodiment that are identical tothe parts of the first embodiment may be omitted for the sake ofbrevity.

The load limiter 334 of the fourth embodiment includes many of thefeatures of the load limiter 34 of the first embodiment, including, thecover 52, the second member 38 (not shown in FIGS. 18 and 19), thebuckle mechanism 40, the clutch mechanism 42 and the pivot pin 58.However, in the fourth embodiment, the first member 36 has been replacedwith a first member 336 that is identical to the first member 36, exceptthat outer side surfaces thereof are provided with gear teeth 380.Further, the load limiter 334 includes a secondary housing 370 thatincludes a slot 370 a and a recessed area 370 b that is dimensioned toreceive the first member 336 and a positioning mechanism that includesmotors 360 (only one motor is shown in FIG. 18) and gears 360 a, asshown in FIG. 19.

The secondary housing 370 is configured to be fixedly attached to theseat structure 26 instead of the first member 336. In other words, thefirst member 336 is movable within the secondary housing 370, while thesecondary housing 370 is fixed to the seat structure 26.

The motor 360 of the position adjusting mechanism is operated to adjustthe position of the first member 336 relative to the secondary housing370 and hence the buckle mechanism 40 for the comfort of the passenger.Specifically, the motors 360 rotate the gears 360 a causing the firstmember 336 to move within the recessed area 370 b of the secondaryhousing 370. When the controller 44 is provided with signals from one orboth of the sensors 46 and 48 indicating a tensioning event, the motor360 does not need to be released as the released positions possible forthe movement of the buckle mechanism 40 remain as described with respectto the first embodiment.

The controller 44 is configured to operate the electronic motor 260 ofthe third embodiment and the electronic motors 360 of the fourthembodiment in response to position related inputs made by the passengerto position the buckle mechanism 40 to a comfortable location relativeto the seat structure 26.

The controller 44 preferably includes a microcomputer with a loadlimiter and airbag control program that controls the operation of theclutch mechanisms and airbags described above. The controller 44 canalso include other conventional components such as an input interfacecircuit, an output interface circuit, and storage devices such as a ROM(Read Only Memory) device and a RAM (Random Access Memory) device. Themicrocomputer of the controller 44 is programmed to control the clutchmechanisms and airbags. The memory circuit stores processing results andcontrol programs such as ones for load limiter and airbag operation thatare run by the processor circuit. The controller 44 is operativelycoupled to the load limiter, the positioning mechanisms and the airbagsin a conventional manner. The internal RAM of the controller 44 storesstatuses of operational flags and various control data. It will beapparent to those skilled in the art from this disclosure that theprecise structure and algorithms for the controller 44 can be anycombination of hardware and software that will carry out the functionsof the present invention.

The various vehicle structures of the vehicle 10 are conventionalcomponents that are well known in the art. Since vehicle structures arewell known in the art, these structures will not be discussed orillustrated in detail herein. Rather, it will be apparent to thoseskilled in the art from this disclosure that the components can be anytype of structure and/or programming that can be used to carry out thepresent invention.

General Interpretation of Terms

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Also as used herein to describe theabove embodiments, the following directional terms “forward”,“rearward”, “above”, “downward”, “vertical”, “horizontal”, “below” and“transverse” as well as any other similar directional terms refer tothose directions of a vehicle equipped with the vehicle seatbeltassembly. Accordingly, these terms, as utilized to describe the presentinvention should be interpreted relative to a vehicle equipped with thevehicle seatbelt assembly.

The term “detect” as used herein to describe an operation or functioncarried out by a component, a section, a device or the like includes acomponent, a section, a device or the like that does not requirephysical detection, but rather includes determining, measuring,modeling, predicting or computing or the like to carry out the operationor function.

The term “configured” as used herein to describe a component, section orpart of a device includes hardware and/or software that is constructedand/or programmed to carry out the desired function.

The terms of degree such as “substantially”, “about” and “approximately”as used herein mean a reasonable amount of deviation of the modifiedterm such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. For example, the size, shape, location ororientation of the various components can be changed as needed and/ordesired. Components that are shown directly connected or contacting eachother can have intermediate structures disposed between them. Thefunctions of one element can be performed by two, and vice versa. Thestructures and functions of one embodiment can be adopted in anotherembodiment. It is not necessary for all advantages to be present in aparticular embodiment at the same time. Every feature which is uniquefrom the prior art, alone or in combination with other features, alsoshould be considered a separate description of further inventions by theapplicant, including the structural and/or functional concepts embodiedby such features. Thus, the foregoing descriptions of the embodimentsaccording to the present invention are provided for illustration only,and not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

What is claimed is:
 1. A vehicle seatbelt assembly comprising: a loadlimiter having a seatbelt attachment portion and a seatbelt tensioncontrol mechanism that is configured to increase the length of ashoulder portion of a seatbelt in response to rapid or suddendeceleration of a vehicle, thereby reducing a level of tensionexperience by a seatbelt, the seatbelt tension control mechanism furtherincluding a clutch mechanism disposed between the first member and thesecond member, the clutch mechanism being operable to switch between adis-engaged state allowing movement of the second member relative to thefirst member and an engaged state preventing movement of the secondmember relative to the first member.
 2. The vehicle seatbelt assemblyaccording to claim 1, wherein the seatbelt tension control mechanismincludes a first member configured to attach to one of a vehicle floorstructure and a seat structure and a second member supported on thefirst member, the second member being configured for limited slidingmovement relative to the first member.
 3. The vehicle seatbelt assemblyaccording to claim 2, wherein the seatbelt attachment portion is definedby a buckle mechanism attached to the second member for movementtherewith, the buckle mechanism having a latch device configured toreleasably retain a seatbelt latch tongue member of the seatbelt.
 4. Thevehicle seatbelt assembly according to claim 1, wherein the clutchmechanism includes a magnetorheological fluid that is electronicallyactivated such that with an electric current being provided to theclutch mechanism, the clutch is in the engaged state, and in the absenceof an electric current being provided to the clutch mechanism the clutchis in the dis-engaged state.
 5. The vehicle seatbelt assembly accordingto claim 4, wherein the second member is spring biased to move toward afirst orientation relative to the first member, and the clutch mechanismis configured to retain the second member in the first orientationrelative to the first member.
 6. The vehicle seatbelt assembly accordingto claim 4, further comprising: an electronic controller connected tothe clutch mechanism, the controller being configured to operate theclutch mechanism to change from the engaged state to the dis-engagedstate in response to detection of a tensioning event.
 7. The vehicleseatbelt assembly according to claim 6, wherein the tensioning event isone of the following: a rapid deceleration of the vehicle bodystructure, a hard-braking event and an impact event.
 8. The vehicleseatbelt assembly according to claim 6, wherein the buckle mechanism isattached to the second member via a coupling member such that the bucklemechanism is a first distance away from the first member by apredetermined distance with the clutch mechanism in the engaged state,and in response to the controller operating the clutch mechanism tochange from the engaged state to the dis-engaged state movement of thesecond member relative to the first member changes the location of thebuckle mechanism such that with the clutch mechanism in the dis-engagedstate the buckle mechanism is a second distance away from the firstmember, the second distance being greater than a first distance.
 9. Avehicle seatbelt assembly comprising: a seat structure configured toinstall a floor structure of a passenger compartment of a vehicle; aseatbelt having a first end fixed to one of the floor structure or theseat structure and a shoulder portion spaced apart from the first end; aload limiter having a seatbelt attachment portion and a seatbelt tensioncontrol mechanism that are attached to the seat structure along one sideof a seat cushion portion of the seat structure, the seatbelt attachmentportion being connectable to the shoulder portion of the seatbelt, theseatbelt tension control mechanism being configured to increase thelength of the shoulder portion of the seatbelt in response to rapid orsudden deceleration of a vehicle, thereby reducing a level of tensionexperience by a seatbelt.
 10. The vehicle seatbelt assembly according toclaim 9, wherein the load limiter further includes the following: afirst member attached to the one of floor structure or the seatstructure; a second member supported on the first member and beingattachable to the shoulder portion of the seatbelt, the second memberbeing configured for limited sliding movement relative to the firstmember; and a clutch mechanism disposed between the first member and thesecond member, the clutch mechanism being operable to switch between adis-engaged state allowing movement of the second member relative to thefirst member and an engaged state preventing movement of the secondmember relative to the first member.
 11. The vehicle seatbelt assemblyaccording to claim 10, wherein the seatbelt attachment portion includesa buckle mechanism attached to the second member for movement therewith;and the shoulder portion of the seatbelt having a seatbelt latch tonguemember that is configured to releasably attach to the buckle mechanism.12. The vehicle seatbelt assembly according to claim 10, wherein theclutch mechanism includes a magnetorheological fluid that iselectronically activated such that with an electric current beingprovided to the clutch mechanism, the clutch is in the engaged state,and in the absence of an electric current being provided to the clutchmechanism the clutch is in the dis-engaged state.
 13. The vehicleseatbelt assembly according to claim 10, wherein the second member isspring biased to move toward an at rest position relative to the firstmember, and the clutch mechanism is configured to retain the secondmember in the at rest position relative to the first member.
 14. Thevehicle seatbelt assembly according to claim 10, further comprising: anelectronic controller connected to the clutch mechanism, the controllerbeing configured to operate the clutch mechanism to change from theengaged state to the dis-engaged state in response to detection of atensioning event.
 15. The vehicle seatbelt assembly according to claim14, wherein the tensioning event is one of the following: a rapiddeceleration of the vehicle body structure, a hard-braking event and animpact event.
 16. The vehicle seatbelt assembly according to claim 14,wherein the buckle mechanism is attached to the second member via acoupling member such that the buckle mechanism is a first distance awayfrom the first member by a predetermined distance with the clutchmechanism in the engaged state, and in response to the controlleroperating the clutch mechanism to change from the engaged state to thedis-engaged state movement of the second member relative to the firstmember changes the location of the buckle mechanism such that with theclutch mechanism in the dis-engaged state the buckle mechanism is asecond distance away from the first member, the second distance beinggreater than a first distance.
 17. The vehicle seatbelt assemblyaccording to claim 14, wherein the first member includes a positioningmechanism configured to adjust an at rest position of the second memberrelative to the first member; and the clutch mechanism is configured toretain the second member in the at rest position.
 18. The vehicleseatbelt assembly according to claim 17, wherein the positioningmechanism includes an electronic motor connected to the controller, andthe controller is configured to operate the electronic motor duringadjustment of the second member to the at rest position.
 19. The vehicleseatbelt assembly according to claim 18, wherein the controller isconfigured to operate the electronic motor to release the second membersuch that the second member can move with respect to the first member inresponse to the controller operating the clutch mechanism to change fromthe engaged state to the dis-engaged state.